Conference presentation
Coupling infrared gas analysis and cavity ring-down spectroscopy for autonomous measurements of DIC and δ13C-DIC
ASLO Aquatic Sciences Meeting (Honolulu, USA, 26/02/2017 - 03/03/2017)
28/02/2017
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Abstract
The coupled high-resolution measurement of dissolved inorganic carbon (DIC) and its carbon stable isotope ratio (δ13C-DIC) can provide insights into aquatic carbon cycling (e.g. production/respiration, air-water gas exchange), helping elucidate flows of carbon within and between reservoirs. A new method to autonomously determine concentrations of DIC and δ13C-DIC is presented. The simple method requires no customised design, instead it uses two commercially available instruments currently used in aquatic carbon research. An inorganic carbon analyser utilising non-dispersive infrared detection (AIRICA) is coupled to a Cavity Ring-down Spectrometer (Picarro) to determine DIC and δ13C-DIC based on the liberated CO2 from acidified aliquots of water. Using a small sample volume of 2 ml, the precision and accuracy of the new method was comparable to standard laboratory-based isotope ratio mass spectrometry (IRMS) methods. The system achieved a sampling resolution of 16 mins, with a DIC precision of ± 1.5 to 2 µmol kg-1 and δ13C-DIC precision of ± 0.14 ‰ for concentrations spanning 1000 to 3600 µmol kg-1. Accuracy of 0.1 ± 0.06 ‰ based on DIC concentrations ranging from 2000 µmol kg-1 to 2250 µmol kg-1 was achieved during a laboratory-based algal bloom experiment. The high precision data that can be autonomously obtained by the system should enable complex carbonate system questions to be explored using high temporal resolution observations.
Details
- Title
- Coupling infrared gas analysis and cavity ring-down spectroscopy for autonomous measurements of DIC and δ13C-DIC
- Creators
- Mitchell Call - Southern Cross UniversityKai Schulz - Southern Cross UniversityMatheus C Carvalho - Southern Cross UniversityIsaac R Santos - Southern Cross UniversityDamien T Maher - Southern Cross University
- Conference
- ASLO Aquatic Sciences Meeting (Honolulu, USA, 26/02/2017 - 03/03/2017)
- Identifiers
- 991012845997202368
- Academic Unit
- Faculty of Science and Engineering; Centre for Coastal Biogeochemistry; National Marine Science Centre; School of Environment, Science and Engineering; Science
- Resource Type
- Conference presentation